Reservoir property maps, such as oil-in-place, have been utilized for decades with the goal of drilling the best locations, predicting well performance, and improving field development strategies. This traditional workflow uses reservoir properties to estimate well deliverability which is correlated to EUR (Expected Ultimate Recovery). However, EUR predicted using this workflow usually has limited accuracy due to the dynamics and complexity of unconventional reservoirs. An innovative, inverse approach is developed that predicts EUR with a previously unattainable ~75% accuracy by using geochemical data from produced oils. Initially this approach ignores reservoir mapping, understanding that calculated oil-in-place does not equate to producible oil, and instead takes a statistical approach.

Geochemically derived drainage profiles of 200+ Anadarko Basin producing wells were evaluated to quantitatively identify key producing intervals which can then be identified using publicly available vertical logs from historical wells. Multivariate analysis techniques are then applied to the geochemical drainage and log data from these key contributing zones, allowing for identification of variables that have strong correlations to EUR. These variables were used to generate a RPI (Reservoir Productivity Index) and a RPI contour map. More than ten new locations have been drilled using the RPI contour maps and have all met or exceeded EUR predictions, further proving the reliability of this workflow to achieve production goals.

This methodology also revolutionizes the way oil fingerprinting data is typically utilized. High-resolution oil fingerprinting uses the thousands of naturally occurring compounds in produced oils to calculate quantitative production allocation, which then is used to generate drainage profiles. Traditionally, oil fingerprinting technology is a passive reservoir monitoring tool without the ability to predict new well performance. However, by calibrating the EUR prediction model using production allocation results from actual production of 200+ wells, this "history-matched" RPI model is now able to make more accurate predictions of future well performance.

Key conclusions include: 1) averaged production allocation of over 200 Anadarko Basin wells shows: Meramec and Osage targeted wells drained ~20-45% Upper Meramec, ~25% Lower Meramec, and ~30-35% Osage, higher landed wells show ~10-25% shallower drainage; Woodford targeted wells drained ~15-30% total Meramec, ~30% Osage, ~20-30% Woodford, and ~15-25% Hunton; 2) an innovative method was developed using data analytics of drainage profiles from 200+ wells and vertical logs to build a RPI contour map which predicts EUR with ~75%+ accuracy and is proven reliable by more than ten newly drilled locations; and 3) the impact of frac hits to parent wells can be quantified using geochemical data, one case showing as much as ~20% drainage change that lasted for several weeks.

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